• Journal of Internet Computing and Services
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• v.9 no.2
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• pp.83-88
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• 2008

Session initiation protocol (SIP) is an application-layer prolocol to initiate and control multimedia client session. When client ask to use a SIP service, they need to be authenticated in order to get service from the server. Authentication in a SIP application is the process in which a client agent present credentials to another SIP element to establish a session or be granted access to the network service. In 2005, Yang et al. proposed a key exchange and authentication scheme for use in SIP applications, which is based on the Diffie-Hellman protocol. But, Yang et al.'s scheme is not suitable for the hardware-limited client and severs, since it requires the protocol participant to perform significant amount of computations (i.e., four modular exponentiations). Based on this observation. Huang and Wei have recently proposed a new efficient key exchange and authentication scheme thor improves on Yang et al.'s scheme. As for security, Huang and Wei claimed, among others, that their scheme is resistant to offline dictionary attacks. However, the claim turned out to be untrue. In this paper, we show thor Huang and Wei's key exchange and authentication scheme is vulnerable to on offline dictionary attack and forward secrecy.

• Journal of Digital Convergence
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• v.14 no.11
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• pp.143-148
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• 2016

There is increasing concern about security as a need for increased safety in the information industry society. However, it does not meet the needs for safety including CCTV. Therefore, in this paper, we link the processing technology using the image information to the IPS system consisting of GPS and Beacon. It designed a conventional RFID tag attached discomfort and image tracking system is limited to complement the disadvantages identifiable area. To this end, we designed a smart device and the Internet of Things convergence system and a research to ensure the accuracy and reliability of the IPS of the access control system. Finally, by leveraging intelligent video information using a PTZ camera, and set the entrant management policies it was carried out to control the situation and control. Also, by designing the integrated video tracking system, an authentication server, visualization systems were designed to establish an efficient technique for analyzing the IPS entrant behavior patterns.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.694-697
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• 2008

A retaining wall system suitable for a construction project is selected on the basis of subsoil conditions. If the decision-maker selects an improper system, it has a negative effect on the cost and schedule of the construction project. There have been many studies related to the models and processes for selecting optimal retaining wall systems. However, engineers who are not familiar with formal analysis methods could not easily utilize the formal methods proposed by previous studies. In order to overcome this problem, we developed a web-based decision support system called Dr. Underground, which is both physically and technically easily accessible by engineers. Dr. Underground was developed based on a selection method developed from a precedent research project. It was developed using a server-side web language ASP.NET and MS Access as a database. Decision-makers can input data about the building's condition, construction site conditions and adjacent site conditions in this system. Based on the input data, Dr. Underground recommends an optimal retaining wall system for the inputted conditions and provides detail information on the system.

• International journal of advanced smart convergence
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• v.7 no.3
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• pp.23-36
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• 2018

In wireless communication, efficient spectrum usage is an issue that has been an attractive research area for many technologies. Recently new technologies innovations allow compact radios to transmit with power efficient communication over very long distances. For example, Low-Power Wide Area Networks (LPWANs) are an attractive emerging platform to connect the Internet-of-Things (IoT). Especially, LoRa is one of LPWAN technologies and considered as an infrastructure solution for IoT. End-devices use LoRa protocol across a single wireless hop to communicate to gateway(s) connected to the internet which acts as a bridge and relays message between these LoRa end-devices to a central network server. The use of the (ISM) spectrum sharing for such long-range networking motivates us to implement spectrum sensing testbed for cognitive radio network based on LoRa and GNU radio. In cognitive radio (CR), secondary users (SUs) are able to sense and use this information to opportunistically access the licensed spectrum band in absence of the primary users (PUs). In general, PUs have not been very receptive of the idea of opportunistic spectrum sharing. That is, CR will harmfully interfere with operations of PUs. Subsequently, there is a need for experimenting with different techniques in a real system. In this paper, we implemented spectrum sensing for cognitive radio networks based on LoRa and GNU Radio, and further analyzed corresponding performances of the implemented systems. The implementation is done using Microchip LoRa evolution kits, USRPs, and GNU radio.

• The Journal of Korean Association of Computer Education
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• v.10 no.6
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• pp.39-49
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• 2007

In this paper, a web-based, advanced education system for embedded systems have been implemented, which provide students reality through remote controlled experiment environment when they conduct experiments through web, in addition to the creative multimedia contents. Students can use the server-side remote experiment environment through telnet client using Java technology to conduct a variety of experiments on the embedded system remotely. Our system can be used as economical education tools for expensive experiment equipments in shared fashion through web as well as effective and convenient ones for embedded systems anywhere and anytime when internet access is available, compensating for lack in reality of virtual educations.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.3
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• pp.700-712
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• 2011

Due to recently advanced electrical devices, human can access computer network regardless of working location or time restriction. However, currently widely used mouse, joystick, and trackball input system are not easy to carry and they bound user hands exclusively within working space. Those make user inconvenient in Ubiquitous environments.. In this paper, we propose multiple dimension human motion detection system based on wireless sensor networks. It is a portable input device and provides easy installation process and unbinds user hands during input processing stages. Our implemented system is comprised of three components. One is input unit that senses user motions and transmits collected data to receiver. Second is receiver that conveys the received data to application, which runs on server computer. Third is application that performs command operations according to received data. Experiments shows that proposed system accurately detect the characteristics of user arm motions and fully support corresponding input requests.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.6
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• pp.491-496
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• 2015

Cloud computing has emerged with promise to decrease the cost of server additional cost and expanding the data storage and ease for computer resource sharing and apply the new technologies. However, Cloud computing also raises many new security concerns due to the new structure of the cloud service models. Therefore, the secure user authentication is required when the user is using cloud computing. This paper, we propose the enhanced AdaBoost algorithm for access cloud security zone. The AdaBoost algorithm despite the disadvantage of not detect a face inclined at least 20, is widely used because of speed and responsibility. In the experimental results confirm that a face inclined at least 20 degrees tilted face was recognized. Using the FEI Face Database that can be used in research to obtain a result of 98% success rate of the algorithm perform. The 2% failed rate is due to eye detection error which is the people wearing glasses in the picture.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.286-289
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• 2016

In this paper, we propose an architecture that affords mobile app based on nomadic smartphone using not only mobile cloud computing- architecture but also a dedicated web platform called Node.js built-in with the asynchronous, Nonblocking, Event-Driven programming paradigm. Furthermore, the design of the proposed architecture takes document oriented database known as MongoDB to deal with the large amount of data transmit by users of mobile web access application. The Node.js aims to give the programmers the tools needed to solves the large number of concurrent connections problem. We demonstrate the effectiveness of the proposed architecture by implementing an android application responsible of real time analysis by using a vehicle to applications smart phones interface approach that considers the smartphones to acts as a remote users which passes driver inputs and delivers output from external applications.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.2B
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• pp.107-118
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• 2009

In this paper, we present design and implementation for identification and location tracking techniques for vehicle information terminals in high-speed mobile environment using IEEE 802.11 wireless LAN technology. RSU be installed at a specific point. RSU recognizes it and then aware identification and location tracking for target vehicle when target vehicle that is equipped with information terminals pass near point. Issue of quick recognition using IEEE 802.11 access management frame, issue of weak wireless LAN security and tracking a range of restrictions be raised and we present solutions. Vehicle information terminal, RSU and a server-side GUI-based management program be implemented based on proposed solution. Implementation system be performed experiment at actual road environment and effectiveness be verified.

• Convergence Security Journal
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• v.8 no.4
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• pp.41-49
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• 2008

VoIP is a service that changes the analogue audio signal into a digital signal and then transfers the audio information to the users after configuring it as a packet; and it has an advantage of lower price than the existing voice call service and better extensibility. However, VoIP service has a system structure that, compared to the existing PSTN (Public Switched Telephone Network), has poor call quality and is vulnerable in the security aspect. To make up these problems, TLS service was introduced to enhance the security. In practical system, however, since QoS problem occurs, it is necessary to develop the VoIP security system that can satisfy QoS at the same time in the security aspect. In this paper, a user authentication VoIP system that can provide a service according to the security and the user through providing a differential service according to the approach of the users by adding AA server at the step of configuring the existing VoIP session is suggested. It was found that the proposed system of this study provides a quicker QoS than the TLS-added system at a similar level of security. Also, it is able to provide a variety of additional services by the different users.